The American version of s20 often fails to make a phone call.

1, try to shut down and restart.

2. Replace the mobile phone access point (settings, wireless and network, mobile network, access point name, click the menu button in the lower left corner and reset to the default settings).

3. Back up mobile phone data (phone book, SMS, multimedia files, etc.). ) and restore the factory settings (settings, privacy and factory settings). If the above information can't help you, I suggest you send your mobile phone to the nearest mobile phone service center for inspection and maintenance.